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| author | Ashutosh Dixit <ashutosh.dixit@intel.com> | 2015-11-18 02:55:37 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-02-08 09:53:40 +0300 |
| commit | f38e87e8c8d326ec6cddfc3f286b605d996a52a3 (patch) | |
| tree | 53e4b89cefab1d0183f7f380668d8e6862426cd9 /drivers/misc | |
| parent | 3f040887a8be0c28a099a9106bc29443d4f79a7e (diff) | |
| download | linux-f38e87e8c8d326ec6cddfc3f286b605d996a52a3.tar.xz | |
misc: mic: Fix crash when MIC reset is invoked in RESET_FAILED state
This patch fixes the following crash seen when MIC reset is invoked in
RESET_FAILED state due to device_del being called a second time on an
already deleted device:
[<ffffffff813b2295>] device_del+0x45/0x1d0
[<ffffffff813b243e>] device_unregister+0x1e/0x60
[<ffffffffa040f1c2>] scif_unregister_device+0x12/0x20 [scif_bus]
[<ffffffffa042f75a>] cosm_stop+0xaa/0xe0 [mic_cosm]
[<ffffffffa042f844>] cosm_reset_trigger_work+0x14/0x20 [mic_cosm]
The fix consists in realizing that because cosm_reset changes the
state to MIC_RESETTING, cosm_stop needs the previous state, before it
changed to MIC_RESETTING, to decide whether a hw_ops->stop had
previously been issued. This is now provided in a new cosm_device
member cdev->prev_state.
Reviewed-by: Sudeep Dutt <sudeep.dutt@intel.com>
Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/misc')
| -rw-r--r-- | drivers/misc/mic/bus/cosm_bus.h | 2 | ||||
| -rw-r--r-- | drivers/misc/mic/cosm/cosm_main.c | 13 |
2 files changed, 11 insertions, 4 deletions
diff --git a/drivers/misc/mic/bus/cosm_bus.h b/drivers/misc/mic/bus/cosm_bus.h index f7c57f266916..8b6341855dc3 100644 --- a/drivers/misc/mic/bus/cosm_bus.h +++ b/drivers/misc/mic/bus/cosm_bus.h @@ -30,6 +30,7 @@ * @attr_group: Pointer to list of sysfs attribute groups. * @sdev: Device for sysfs entries. * @state: MIC state. + * @prev_state: MIC state previous to MIC_RESETTING * @shutdown_status: MIC status reported by card for shutdown/crashes. * @shutdown_status_int: Internal shutdown status maintained by the driver * @cosm_mutex: Mutex for synchronizing access to data structures. @@ -55,6 +56,7 @@ struct cosm_device { const struct attribute_group **attr_group; struct device *sdev; u8 state; + u8 prev_state; u8 shutdown_status; u8 shutdown_status_int; struct mutex cosm_mutex; diff --git a/drivers/misc/mic/cosm/cosm_main.c b/drivers/misc/mic/cosm/cosm_main.c index 4b4b356c797d..7005cb1e01d2 100644 --- a/drivers/misc/mic/cosm/cosm_main.c +++ b/drivers/misc/mic/cosm/cosm_main.c @@ -153,8 +153,10 @@ void cosm_stop(struct cosm_device *cdev, bool force) * stop(..) calls device_unregister and will crash the system if * called multiple times. */ - bool call_hw_ops = cdev->state != MIC_RESET_FAILED && - cdev->state != MIC_READY; + u8 state = cdev->state == MIC_RESETTING ? + cdev->prev_state : cdev->state; + bool call_hw_ops = state != MIC_RESET_FAILED && + state != MIC_READY; if (cdev->state != MIC_RESETTING) cosm_set_state(cdev, MIC_RESETTING); @@ -195,8 +197,11 @@ int cosm_reset(struct cosm_device *cdev) mutex_lock(&cdev->cosm_mutex); if (cdev->state != MIC_READY) { - cosm_set_state(cdev, MIC_RESETTING); - schedule_work(&cdev->reset_trigger_work); + if (cdev->state != MIC_RESETTING) { + cdev->prev_state = cdev->state; + cosm_set_state(cdev, MIC_RESETTING); + schedule_work(&cdev->reset_trigger_work); + } } else { dev_err(&cdev->dev, "%s %d MIC is READY\n", __func__, __LINE__); rc = -EINVAL; |